In general, undercarriages are hinged to the aircraft to move between a deployed position and a retracted position. To stabilize an undercarriage in the deployed position, it is known to make use of a wind-brace member or brace.
In this respect, so-called “breakable” braces are known that comprise two links that are hinged together by means of a central hinge or knee, one of the links having one end hinged to the undercarriage while the other link has one end hinged to the structure of the aircraft. A stabilizer member keeps the two links in alignment when the undercarriage is in the deployed position, thereby stabilizing the undercarriage. In contrast, while the undercarriage is being retracted, the stabilizer member allows the links to hinge freely at the knee, thereby enabling the brace to be folded and the undercarriage to be retracted.
In conventional manner, the stabilizer member itself comprises two hinged-together arms, one of the arms having one end hinged to one of the arms of the brace, the other arm having one end hinged to the structure of the aircraft. Abutments define a locked position in which said arms are substantially in alignment. A spring member holds the arms of the stabilizer member in the locked position. The assembly forms a locking device that enables the brace to be held in the aligned position.
An unlocking actuator working against the springs enables the alignment between the arms of the stabilizer member to be broken, and thus enables the brace to be folded. The prior art is illustrated in particular by the following documents: U.S. Pat. Nos. 5,022,609; 2,661,171; GB 704 080; and GB 644 147.